The Experts below are selected from a list of 162 Experts worldwide ranked by ideXlab platform
Rui Curi - One of the best experts on this subject based on the ideXlab platform.
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METABOLIC FATE AND EFFECTS OF SATURATED AND UNSATURATED FATTY ACIDS IN HEP2 HUMAN Larynx Tumor CELLS
Iubmb Life, 1997Co-Authors: Alison Colquhoun, Rui CuriAbstract:Previous studies have reported the presence of carnitine palmitoyltransferase 1 and II in Tumor cells and the inhibitory effects of fatty acids on cell proliferation. The present work considered the metabolic fate of [14C] or [3HI-labeled fatty acids and their effects on cellular metabolism in Hep2 human Larynx Tumor cells.The rate of uptake of acetate was 45% of that of myristate, paimitate, oleate, iinoleate and arachidonate. However, acetate was rapidly metabolized within the cell as seen by its low rate of accumulation as non-esterified fatty acid,
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metabolic fate and effects of saturated and unsaturated fatty acids in hep2 human Larynx Tumor cells
Iubmb Life, 1997Co-Authors: Alison Colquhoun, Rui CuriAbstract:Previous studies have reported the presence of carnitine palmitoyltransferase 1 and II in Tumor cells and the inhibitory effects of fatty acids on cell proliferation. The present work considered the metabolic fate of [14C] or [3HI-labeled fatty acids and their effects on cellular metabolism in Hep2 human Larynx Tumor cells.The rate of uptake of acetate was 45% of that of myristate, paimitate, oleate, iinoleate and arachidonate. However, acetate was rapidly metabolized within the cell as seen by its low rate of accumulation as non-esterified fatty acid, <5% of that of the other fatty acids. The incorporation of fatty acids into neutral lipid fractions showed palmitate and oleate primarily entered the phospholipid fraction, while linoleate and arachidonate entered equally the phospholipid and triacylglycerol fractions. Palmitate and oleate were oxidized to ~4CO2 at higher rates than linoleate and arachidonate, with arachidonate being the least oxidized of the unsaturated fatty acids. Acetate was oxidized at 10-30 fold higher rates than the other fatty acids. Palmitate, oleate, linoleate and arachidonate all had significant inhibitory effects on the rate of glucose utilization by Hep2 cells, ranging from 25-38% inhibition and were found to inhibit cell proliferation by 17-73%. These findings suggest that certain fatty acids not only play a structural role in cellular metabolism, but may also have a potential regulatory role in the glycolytic pathway of Hep2 cells.
Alison Colquhoun - One of the best experts on this subject based on the ideXlab platform.
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METABOLIC FATE AND EFFECTS OF SATURATED AND UNSATURATED FATTY ACIDS IN HEP2 HUMAN Larynx Tumor CELLS
Iubmb Life, 1997Co-Authors: Alison Colquhoun, Rui CuriAbstract:Previous studies have reported the presence of carnitine palmitoyltransferase 1 and II in Tumor cells and the inhibitory effects of fatty acids on cell proliferation. The present work considered the metabolic fate of [14C] or [3HI-labeled fatty acids and their effects on cellular metabolism in Hep2 human Larynx Tumor cells.The rate of uptake of acetate was 45% of that of myristate, paimitate, oleate, iinoleate and arachidonate. However, acetate was rapidly metabolized within the cell as seen by its low rate of accumulation as non-esterified fatty acid,
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metabolic fate and effects of saturated and unsaturated fatty acids in hep2 human Larynx Tumor cells
Iubmb Life, 1997Co-Authors: Alison Colquhoun, Rui CuriAbstract:Previous studies have reported the presence of carnitine palmitoyltransferase 1 and II in Tumor cells and the inhibitory effects of fatty acids on cell proliferation. The present work considered the metabolic fate of [14C] or [3HI-labeled fatty acids and their effects on cellular metabolism in Hep2 human Larynx Tumor cells.The rate of uptake of acetate was 45% of that of myristate, paimitate, oleate, iinoleate and arachidonate. However, acetate was rapidly metabolized within the cell as seen by its low rate of accumulation as non-esterified fatty acid, <5% of that of the other fatty acids. The incorporation of fatty acids into neutral lipid fractions showed palmitate and oleate primarily entered the phospholipid fraction, while linoleate and arachidonate entered equally the phospholipid and triacylglycerol fractions. Palmitate and oleate were oxidized to ~4CO2 at higher rates than linoleate and arachidonate, with arachidonate being the least oxidized of the unsaturated fatty acids. Acetate was oxidized at 10-30 fold higher rates than the other fatty acids. Palmitate, oleate, linoleate and arachidonate all had significant inhibitory effects on the rate of glucose utilization by Hep2 cells, ranging from 25-38% inhibition and were found to inhibit cell proliferation by 17-73%. These findings suggest that certain fatty acids not only play a structural role in cellular metabolism, but may also have a potential regulatory role in the glycolytic pathway of Hep2 cells.
Rosanna Abbate - One of the best experts on this subject based on the ideXlab platform.
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prostaglandins in squamous cell carcinoma of the Larynx Tumor and periTumor synthesis
Prostaglandins Leukotrienes and Essential Fatty Acids, 1990Co-Authors: S Pinto, Oreste Gallo, M Dilaghi, E Gallina, Augusto Giannini, Mirella Coppo, Rita Paniccia, Domenico Prisco, Rosanna AbbateAbstract:Abstract Prostaglandin (PG) E2, 6ketoPGF 1α and Thromboxane B2 (TxB2) production by the Tumor, periTumor and control tissue were investigated in specimens from patients (n=11) with squamous cell carcinoma of the Larynx, in relation to the extension and infiltration of the neoplasm and to the presence of inflammation, fibrosis and necrosis. In all specimens detectable amounts of 6ketoPGF 1+ and TxB2 were found, but the predominant metabolite was PGE 2 . No differences in the levels of TxB 2 and 6ketoPGF 1α were observed, but the only patient with lymphonodal involvement showed the lowest levels of 6ketoPGF 1α both in Tumor and periTumor tissue. Higher amounts (p 2 were synthesized by periTumor tissues in comparison to control mucosa and Tumor tissue independently of the occurrence of reactive infiltration. PGs synthesis did not correlate with inflammation, fibrosis, necrosis or staging of the neoplasm. However the two cases in stage T4 showed PGE 2 generation at the highest levels both in neoplastic and perineoplastic tissue. These findings indicate that in squamous cell carcinoma of the Larynx an increased production of PGE 2 occurs, stemming not only from inflammatory cells but at least in part from neoplastic cells. This suggests that the study of arachidonic acid metabolism may contribute to characterization of the primary cancer and lead to better understanding of the mechanisms of Tumor growth and diffusion.
Jolyon H Hendry - One of the best experts on this subject based on the ideXlab platform.
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time factors in Larynx Tumor radiotherapy lag times and interTumor heterogeneity in clinical datasets from four centers
International Journal of Radiation Oncology Biology Physics, 1999Co-Authors: Stephen A Roberts, Jolyon H HendryAbstract:Abstract Purpose: To use the time-dependent linear-quadratic model, both in the standard form and in a form modified to incorporate interTumor heterogeneity, in a reanalysis of 4 datasets for Larynx Tumor control, to provide more representative and direct estimates of the lag period, the time factor (λ/α), and the clonogen population inactivation dose ([lnk]/α). Methods and Materials: The data comprised 2,225 patients treated in Edinburgh (UK), Glasgow (UK), Manchester (UK), or Toronto (Canada), with Tumor control assessed after at least 2 years. Heterogeneity in each series was taken into account using the coefficient of variation (CV) of the clonogen radiosensitivity (α). Maximum likelihood techniques were used to provide best estimates of the parameters, and also direct estimation of the more stable parameter ratios of interest. Results: The use of different heterogeneity factors for the different series allowed common dose/time parameters to be fitted across all four series in a way not possible using the standard model, enabling the inherent effect of heterogeneity in flattening dose-response curves and in reducing time factors to be separated from the underlying more-representative values. Radiosensitivity CVs were calculated to be 30% (Edinburgh), 36% (Glasgow), 40% (Manchester), and 71% (Toronto). The lag phase was 32 days (95% CL 20–38 days) which was longer than the value of 23 days (11–36 days) deduced using the standard model without the heterogeneity parameter. The time factor was 1.2 (0.8–2.2) Gy/day, again greater than the value of 0.80 (0.54–1.41) Gy/day derived using the standard model. Similar larger time factors and longer lag periods could be reproduced using the standard model either by using a parameterization based on parameter ratios, or by omitting the discordant Toronto data and refitting just the data from the three UK centers. Conclusion: It was concluded that the heterogeneity model provides a better representation of the time factor for Tumor control when data are analyzed comprising different stages of disease treated at different centers. The model allows different amounts of heterogeneity in different series, which tend to flatten dose-responses curves and reduce time factors, to be taken in to account. Also, direct maximum likelihood estimates can be made of the lag period, the time factor (λ/α), and the fractionation sensitivity (β/α), as well as the clonogen population inactivation dose (lnk)/α. Values of these parameter ratios are more robust and stable than the individual parameter values. The results of the present analysis using a total of 2,225 patients from four centers indicate that the average lag period may be somewhat longer and the average time factor somewhat greater (and the 95% confidence limits of the time factor exclude previous estimates), than the values deduced previously using simpler models and more diverse multi-center datasets.
S Pinto - One of the best experts on this subject based on the ideXlab platform.
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prostaglandins in squamous cell carcinoma of the Larynx Tumor and periTumor synthesis
Prostaglandins Leukotrienes and Essential Fatty Acids, 1990Co-Authors: S Pinto, Oreste Gallo, M Dilaghi, E Gallina, Augusto Giannini, Mirella Coppo, Rita Paniccia, Domenico Prisco, Rosanna AbbateAbstract:Abstract Prostaglandin (PG) E2, 6ketoPGF 1α and Thromboxane B2 (TxB2) production by the Tumor, periTumor and control tissue were investigated in specimens from patients (n=11) with squamous cell carcinoma of the Larynx, in relation to the extension and infiltration of the neoplasm and to the presence of inflammation, fibrosis and necrosis. In all specimens detectable amounts of 6ketoPGF 1+ and TxB2 were found, but the predominant metabolite was PGE 2 . No differences in the levels of TxB 2 and 6ketoPGF 1α were observed, but the only patient with lymphonodal involvement showed the lowest levels of 6ketoPGF 1α both in Tumor and periTumor tissue. Higher amounts (p 2 were synthesized by periTumor tissues in comparison to control mucosa and Tumor tissue independently of the occurrence of reactive infiltration. PGs synthesis did not correlate with inflammation, fibrosis, necrosis or staging of the neoplasm. However the two cases in stage T4 showed PGE 2 generation at the highest levels both in neoplastic and perineoplastic tissue. These findings indicate that in squamous cell carcinoma of the Larynx an increased production of PGE 2 occurs, stemming not only from inflammatory cells but at least in part from neoplastic cells. This suggests that the study of arachidonic acid metabolism may contribute to characterization of the primary cancer and lead to better understanding of the mechanisms of Tumor growth and diffusion.
